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Featured researches published by María A. Martínez.


Forensic Science International | 2008

Reporting a fatality during tumescent liposuction

María A. Martínez; Salomé Ballesteros; Luis J. Segura; Manuel García

Deaths of patients during elective surgery have drawn attention to the danger of anesthesia. Tumescent local anesthesia is subcutaneous infiltration of large volumes of dilute lidocaine with epinephrine to produce vasoconstriction while delivering anesthesia over large areas without lidocaine toxicity. This report documents the case of a 38-year-old woman who attended an outpatient clinic to undergo liposuction of the abdomen and bilateral hips and thighs. According to one witness, around 30 min after anesthesia administration, the victim suffered an episode of tonic-clonic convulsion. When the emergency medical services arrived the patient was in asystole. She died in spite of attempted cardiopulmonary resuscitation. The patient had no significant past medical history including no history of allergies or any known complications with anesthesia. A complete autopsy was performed and possible causes of death such as myocardial infarction, aspiration of food or foreign body, and pulmonary embolism were discarded. Anaphylactic shock was considered a possible but unlikely explanation for the fatality. Toxicological analyses revealed the presence of lidocaine and mepivacaine in heart blood, at concentrations of 4.9 and 16.2mg/L, respectively. All drugs involved in the case were detected using gas chromatography with nitrogen-phosphorus detector and confirmed using gas chromatography-mass spectrometry full scan mode after solid-phase extraction using Chem-Elut columns. An additional high-performance liquid chromatography coupled to diode-array detection screening also obtained the same results. Based on the autopsy findings, case history, and toxicology results, the forensic pathologists ruled that the cause of death was an overdose of local anesthetic agents. The Court of Law ruled the death as an involuntary homicide due to gross negligence.


Forensic Science International | 2014

Xylazine intoxication in humans and its importance as an emerging adulterant in abused drugs: A comprehensive review of the literature

Kazandra Ruiz-Colón; Carlos Chavez-Arias; José Eric Díaz-Alcalá; María A. Martínez

Xylazine is not a controlled substance; it is marketed as a veterinary drug and used as a sedative, analgesic and muscle relaxant. In humans, it could cause central nervous system depression, respiratory depression, bradycardia, hypotension, and even death. There have been publications of 43 cases of xylazine intoxication in humans, in which 21 (49%) were non-fatal scenarios and 22 (51%) resulted in fatalities. Most of the non-fatal cases required medical intervention. Over recent years xylazine has emerged as an adulterant in recreational drugs, such as heroin or speedball (a cocaine and heroin mixture). From the 43 reported cases, 17 (40%) were associated with the use of xylazine as an adulterant of drugs of abuse. Its chronic use is reported to be associated with physical deterioration and skin ulceration. Literature shows some similar pharmacologic effects between xylazine and heroin in humans. These similar pharmacologic effects may create synergistic toxic effects in humans. Therefore, fatalities among drug users may increase due to the use of xylazine as an adulterant. Xylazine alone has proven harmful to humans and even more when it is combined with drugs of abuse. A comprehensive review of the literature of non-fatal and fatal xylazine intoxication cases including those in which the substance was used as adulterant is presented, in order to increase the awareness in the forensic community, law enforcement, and public health agencies.


Journal of Analytical Toxicology | 2012

Simultaneous Determination of Xylazine, Free Morphine, Codeine, 6-Acetylmorphine, Cocaine and Benzoylecgonine in Postmortem Blood by UPLC–MS-MS

Kazandra Ruiz-Colón; María A. Martínez; Luz Silva-Torres; Carlos Chavez-Arias; Margarita Meléndez-Negrón; María S. Conte-Miller; Joseph Bloom-Oquendo

Xylazine, a veterinary sedative, has been found as an adulterant of heroin in street drugs in Puerto Rico. It was found in combination with free morphine and 6-acetylmorphine, codeine, cocaine and benzoylecgonine in postmortem cases at the Puerto Rico Institute of Forensic Sciences (PRIFS). Xylazine is not approved for human use because it has been proven harmful. Currently, three separate analyses are required to determine all the aforementioned drugs at the PRIFSs toxicology laboratory. To reduce analysis time consumption, sample volume, run time, sample preparation and cost, a high-throughput ultra-high-pressure liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous quantification of xylazine, free morphine, 6-acetylmorphine, codeine, cocaine and benzoylecgonine in 0.25 mL postmortem blood by protein precipitation, fulfilling confirmation criteria with three transitions for each compound with acceptable relative ion intensities. Linearity was established between 10-1,000 ng/mL. Total run time was 2.5 min. Limit of detection was 1 ng/mL for cocaine and xylazine, 2 ng/mL for 6-acetylmorphine and 10 ng/mL for free morphine, codeine and benzoylecgonine. The intra-day and inter-day precision and accuracy was less than 15.6%. Process efficiencies ranged from 35.9 to 123.4% and recoveries from 59.9 to 110.1%. The developed method was successfully applied to casework.


Forensic Science International | 2012

Reporting a sudden death due to accidental gasoline inhalation

María A. Martínez; Salomé Ballesteros; Rafael Alcaraz

The investigation of uncertain fatalities requires accurate determination of the cause of death, with assessment of all factors that may have contributed to it. Gasoline is a complex and highly variable mixture of aliphatic and aromatic hydrocarbons that can lead to cardiac arrhythmias due to sensitization of the myocardium to catecholamines or acts as a simple asphyxiant if the vapors displace sufficient oxygen from the breathing atmosphere. This work describes a sudden occupational fatality involving gasoline. The importance of this petroleum distillate detection and its quantitative toxicological significance is discussed using a validated analytical method. A 51 year-old Caucasian healthy man without significant medical history was supervising the repairs of the telephone lines in a manhole near to a gas station. He died suddenly after inhaling gasoline vapors from an accidental leak. Extensive blistering and peeling of skin were observed on the skin of the face, neck, anterior chest, upper and lower extremities, and back. The internal examination showed a strong odor of gasoline, specially detected in the respiratory tract. The toxicological screening and quantitation of gasoline was performed by means of gas chromatography with flame ionization detector and confirmation was performed using gas chromatography-mass spectrometry. Disposition of gasoline in different tissues was as follows: heart blood, 35.7 mg/L; urine, not detected; vitreous humor, 1.9 mg/L; liver, 194.7 mg/kg; lung, 147.6 mg/kg; and gastric content, 116,6 mg/L (2.7 mg total). Based upon the toxicological data along with the autopsy findings, the cause of death was determined to be gasoline poisoning and the manner of death was accidental. We would like to alert on the importance of testing for gasoline, and in general for volatile hydrocarbons, in work-related sudden deaths involving inhalation of hydrocarbon vapors and/or exhaust fumes.


Clinical Toxicology | 2007

A severe case of olanzapine overdose with analytical data

Salomé Ballesteros; María A. Martínez; M. Angeles Ballesteros; Carolina Sánchez de la Torre; Juan C. Rodríguez-Borregán

Introduction. Olanzapine is a second-generation atypical antipsychotic agent approved for the treatment of psychotic disorders and mania. While olanzapine overdoses are common, cases with whole blood concentrations are less so. We describe here a well-documented case of a pure olanzapine overdose in which whole blood concentrations were determined, and compared with other concentrations in the literature. Case report. A 58-year-old woman with a 10-year history of paranoid schizophrenia and poor therapeutic compliance was found unconscious with two empty 28-tablet vials of Zyprexa® (olanzapine) 10 mg tablets. Her initial vital signs were blood pressure 110/70 mmHg, pulse rate 82 beats/minute (sinus rhythm), respirations 20 breaths/minute, and the Glasgow Coma Scale score was 7. In the Intensive Care Unit, her pulse rate was 160 beats/minute, in sinus rhythm, and QTc 0.423 seconds (normal <0.4 seconds). Relevant analytical findings were metabolic acidosis, leukocytosis, creatine phosphokinase 1992 mg/dL, and glucose 207 mg/dL. Ten hours after being found, her blood sugar was 350 mg/dL and became normal at 25 hours. The patient needed intubation and insulin. Results. Olanzapine was detected and quantitated by gas chromatography with nitrogen-phosphorus detector and confirmed by gas chromatography-mass spectrometry using a validated analytical method. At approximately 4, 8, and 12 hours post-ingestion, whole blood concentrations of olanzapine were 0.41, 0.34, and 0.38 mg/L, respectively. Conclusions. This study reports an acute olanzapine monointoxication with severe toxicity and high whole blood olanzapine concentrations. Clinical and analytical data of similar samples obtained in non-fatal life-threatening cases can be very useful when interpreting postmortem cases.


Journal of Analytical Toxicology | 2012

Two Suicidal Fatalities Due to the Ingestion of Chlorfenvinphos Formulations: Simultaneous Determination of the Pesticide and the Petroleum Distillates in Tissues by Gas Chromatography–Flame-Ionization Detection and Gas Chromatography–Mass Spectrometry

María A. Martínez; Salomé Ballesteros

Chlorfenvinphos (CFVP) is an organophosporus insecticide designated as a threat agent by the National Institutes of Health (NIH). However, there are very few reported cases of poisonings in humans and none with postmortem toxicological analysis. We report the first two fatalities due to suicidal massive ingestion of a veterinary formulation containing CFVP and petroleum distillates. Case 1: A 24-year-old woman was found dead by her mother. According to the police records, the room was filled with an odor of solvents or pesticides and feces. There was an empty bottle of Supona(®) near the body and a suicide note on a Bible on a table. The only relevant postmortem finding was that the lungs appeared congested and edematous. Case 2: A 60-year-old man committed in his van by ingesting an unknown product. The vehicle was locked and had an odor that resembled an acid, sulfate, or solvent according to different witnesses. There was a suicide note as well as multiple containers containing automobile products nearby. The stomach of the victim was filled with abundant pale greenish fluid with a similar odor to that presented in the vehicle. The simultaneous toxicological screening and quantitation of CFVP and petroleum distillates [a mixture of trimethylbenzene isomers (TMBs)] was performed by means of gas chromatography with flame-ionization detection (GC-FID) and confirmation was performed using gas chromatography-mass spectrometry (GC-MS). Disposition of CFVP and TMBs in different tissues were, respectively, as follows: Case 1: heart blood, 8.6 and 3.7 mg/L; liver, 60.0 and 33.4 mg/kg; and stomach contents, 1132 mg/L (792.4 mg total) and 377.0 mg/L (263.9 mg total). Case 2: heart blood, 4.4 and 6.5 mg/L; urine, 1.4 and detected (< LOQ); bile 7.8 and 12.2 mg/L; vitreous 0.3 mg/L and detected (< LOQ); liver, 139.2 and 172.1 mg/kg; and stomach contents, 76,168 mg/L (72,359 mg total) and 108,109 mg/L (102,703 mg total). Results of alcohol, other volatiles, abused and therapeutic drugs were negative in both cases. The proposed analytical method allows the simultaneous determination of a wide variety of pesticides and additives, including petroleum distillates suitable for toxicological investigation in forensic and clinical cases. This is crucial to solving poisoning cases in which the poisoning source is uncertain.


Forensic Science International | 2005

Determination of several psychiatric drugs in whole blood using capillary gas-liquid chromatography with nitrogen phosphorus detection: comparison of two solid phase extraction procedures

Carolina Sánchez de la Torre; María A. Martínez; Elena Almarza


Journal of Analytical Toxicology | 2003

A Comparative Solid-Phase Extraction Study for the Simultaneous Determination of Fluoxetine, Amitriptyline, Nortriptyline, Trimipramine, Maprotiline, Clomipramine, and Trazodone in Whole Blood by Capillary Gas—Liquid Chromatography with Nitrogen-Phosphorus Detection

María A. Martínez; C. Sánchez de la Torre; Elena Almarza


Journal of Analytical Toxicology | 2004

A Comparative Solid-Phase Extraction Study for the Simultaneous Determination of Fluvoxamine, Mianserin, Doxepin, Citalopram, Paroxetine, and Etoperidone in Whole Blood by Capillary Gas-Liquid Chromatography with Nitrogen-Phosphorus Detection

María A. Martínez; Carolina Sánchez de la Torre; Elena Almarza


Journal of Analytical Toxicology | 2002

Simultaneous Determination of Viloxazine, Venlafaxine, Imipramine, Desipramine, Sertraline, and Amoxapine in Whole Blood: Comparison of Two Extraction/Cleanup Procedures for Capillary Gas Chromatography with Nitrogen-Phosphorus Detection

María A. Martínez; C. Sánchez de la Torre; Elena Almarza

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